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BULLETIN OF THE BUREAU OF FISHERIES 
so that specimens were probably living in water of lower salinity. No data are given 
as to temperature, since the thermometers used during that cruise were not of the 
reversing type which records bottom temperatures. 
ISOPODA 
As in the case of the amphipods, the species listed below were those taken on 
the May cruise, 1920. They probably represent only part of the species which have 
been collected in later cruises but which have not been studied. The list is as follows : 
Aegathoa oculata (Say), Erichsonella attenuata (Harger), Edotea triloba (Say), Idothea 
baltica (Pallas) and Edotea montosa (Stimpson). 
The first species, Aegathoa oculata, is a parasitic form which is known from New 
England to the West Indies (Richardson, 1905, p. 217) and which was found at 
Crisfield, Md., years ago. We collected this form at area B, off Cape Charles City. 
No fish were caught at this station, and the records do not indicate that the speci- 
men was attached to anything at the time of capture. 
So far as records from various sources show, the isopod Erichsonella attenuata is 
not widely distributed. It is known to frequent eelgrass along the coast of New j 
Jersey and Connecticut but, according to Harger (1878, p. 357), it has not been found 
north of Cape Cod. The studies of Wallace (1919), Macdonald (1912), and Stimpson 
(1853) do not show its occurrence along the Atlantic coast of Canada. During 
our May, 1920, cruise it was taken at area Z, not far from Baltimore. The salinity 
of the water in that region did not exceed 6.00 per mille. As pointed out by Harger, 
the known distribution of this form indicates that it is a southern form. 
Edotea triloba, another isopod which Harger (1880, p. 429) speaks of as a southern 
form, since that time has been found very abundant in the Bay of Fundy between low- 
tide mark and 15 fathoms (Wallace, 1919). It has been collected along the coast 
from Maine to New Jersey in shallow water and was taken in Chesapeake Bay at 
areas G and C. The depths and bottom salinities at these areas w ere 24 meters, 25.77 
per mille, and 13 meters, 20.65 per mille, respectively. Apparently it may be found on 
almost any sort of bottom. 
The cosmopolitan isopod, Idothea baltica, has been found along the Atlantic 
coast of Canada and the United States as far south as North Carolina at least. In 
Chesapeake Bay it was caught at areas A and B, not far from the mouth of the bay. 
The depths at these areas were 13 meters and 40 meters; the salinities, 24.33 per mille 
and 29.34 per mille (at 39 meters), respectively. 
Another species of Edotea, E. montosa, which is considered by Wallace (1919, p. 
26) as grading into E. triloba and E. acuta and which has been known heretofore from 
Long Island Sound to the Bay of Fundy, was taken at area A under the same condi- 
tions as Idothea baltica. This species had been classed by Harger (1880, p. 429) 
as a northern form. 
SCHIZOPODA 
The Schizopoda are represented in Chesapeake Bay by the well-known species 
Neomysis americana (Smith), formerly called My sis americana, and two other species — 
one Mysidopsis bigellowi Tattersall and another which will be designated as Alysidop- 
sis sp. nov. until it has been studied and described by Doctor Tattersall. The last 
two species are quite uncommon in our collections, but Neomysis americana was 
taken on every cruise during the year (1920), and there is much evidence to indicate 
that it is endemic in Chesapeake Bay. 
